“Emergency Law Enforcement Officer Hologram program activated. Please state the nature of your criminal or civil emergency.” Taking a cue from Star Trek: Voyager, the Seoul Metropolitan Police Agency is testing a holographic police officer, with surprisingly — dare we say, suspiciously? — positive results. The virtual officer makes an appearance every two minutes in the evening hours in a public park, presumably one with a history of criminal activity. The projection is accompanied by a stern warning that the area is being monitored with cameras, and that should anything untoward transpire, meat-based officers, presumably wearing something other than the dapper but impractical full-dress uniform the hologram sports, will be dispatched to deal with the issue.

The projected police officer is the product of the South Korean firm Hologramica, which seems to be focused on bringing obsolete or metabolically challenged pop and sports stars back to life. The company uses one of two techniques for its 3D projection: the tried and true “Pepper’s Ghost” trick or a proprietary method they call “3D Holonet.” Given the conditions, we’d guess the police projection is using the latter, which uses a transparent screen with metallic silver embedded into it. Aside from the cool factor, we’re not sure how this is better than something as simple as a cardboard cutout with a cop printed on it, or even just some signs telling people to watch their step. Then again, maybe Starbucks will consider employing the holo-cops in their South Korean stores to deal with their cagonjok problem.

“The first rule of Robo Fight Club is: you don’t talk about Robo Fight Club.” Unfortunately, that rule won’t work when you’re trying to create the world’s premier cyber blood sport, as a fellow named Cix Liv — that’s “109 54” in Roman numerals for those of you keeping score at home — aims to do. His outfit is called REK, which he claims will be “the next UFC,” referring to the wildly popular mixed martial arts organization. To meet that improbable goal, he stages fights between humanoid robots controlled by VR-wearing pilots. There’s a video clip of the action in the article; perhaps as humanoid bots get better, so will the fights, but for now, the action is a little tame for our tastes. But what would really jazz things up is human versus robot fights. We’d pay to see someone mix it up with Atlas. Maybe not the original electro-hydraulic version, though — that would probably get out of hand pretty fast.

We stumbled across a really interesting article on Arthur A. Collins, someone whose name will likely only ring a bell among aficionados of old amateur radio gear. The Collins Radio Company produced legendary ham radio equipment from the 1930s all the way into the 1970s. Their bulky, vacuum tube “boat anchor” radios are still highly prized among collectors, long after the company was absorbed into a series of corporations with less and less interest in radio communications. The article details the genesis of Collins Radio, including the shortwave exploits of a 15-year-old Arthur Collins, who in 1925 used his homebrew 1,000-watt transmitter to contact the National Geographic Society’s expedition to Greenland. It’s a fascinating story and aptly illustrates how a passion for electronics can lead to pretty important breakthroughs, even if you’re just a teenager in your parents’ attic.

How do you cut your onions? It’s not an unimportant question, at least if you care enough about your cooking that your onions are diced evenly to ensure proper cooking. However you’re doing it, though, you’re probably wrong, at least according to this wonderfully but needlessly in-depth look at the mathematics of onion dicing. The analysis looks at an optimized cross-section of an onion and determines the best way to cut it to achieve maximum uniformity in the resulting dices. The diagrams are interactive, allowing you to adjust the number of vertical or radial cuts and categorize the results based on the standard deviation in the area of the pieces. It’s an impressive bit of work, with the obvious limitation of simplifying the onion to two dimensions. But with that awesome onion font, we can forgive a lot.

And finally, when you think of instruments played with a bow, you probably think of violins, cellos, and the like. What doesn’t spring to mind is bow-played open-reel tape decks, but it turns out that they’re a thing, and they’re pretty cool. The Open Reel Ensemble has three classic open-reel decks, which look like Pioneer RT-1011Ls, each of which has a length of tape fed through the heads and around one reel. The ends of the tape are attached to either end of a bamboo pole, which the artist holds taut and moves back and forth through the heads. Whatever signals are on the tape — we assume it’s just simple tones — gets played back and piped into a keyboard synth, which the artist plays with his other hand. One of the decks also has a mic attached near the heads, which seems to pick up the sound of the artist thumping on the bow, delivering a nice rhythm section. It’s a unique and surprisingly funky sound. Enjoy!